1. Field of the Invention
The present invention relates to a method and apparatus for manufacturing an organic EL device including an organic layer on an electrode layer formed on a substrate and emitting light from the organic layer.
2. Description of the Related Art
In recent years, organic EL (electroluminescence) devices are drawing attention as devices for use in next-generation low-power-consumption light-emitting display apparatuses. Basically, organic EL devices each include at least one organic layer including a light-emitting layer made of an organic light-emitting material and a pair of electrodes. Such organic EL devices emit light in various colors depending on the organic light-emitting materials. Furthermore, because of being self-light-emitting devices, the organic EL devices are drawing attention for use in displays such as those of televisions (TV).
An organic EL device includes at least one organic layer including a light-emitting layer, sandwiched between two electrode layers having polarities opposite to each other (sandwich structure), and the at least one organic layer includes an organic film having a thickness of several nanometers to several tens of nanometers. Furthermore, the organic layer sandwiched between the electrode layers is supported on a substrate, that is, the anode layer (electrode layer), the organic layer and the cathode layer are deposited on the substrate in this order to form an organic EL device. In the case of a plurality of organic layers included in an organic EL device, an anode layer is formed on a substrate, organic layers are sequentially deposited on the anode layer, and then a cathode layer is formed on the deposited organic layers, thereby forming an organic EL device.
As methods for forming organic layers on an anode layer formed on a substrate in manufacturing such organic EL device, vacuum vapor deposition and film coating are generally known. Among these methods, vacuum vapor deposition is mainly used because the purity of materials for forming the organic layers (organic layer forming materials) can be increased, facilitating provision of long-life products.
In vacuum vapor deposition as mentioned above, a vapor deposition source is provided for each organic layer at a position facing a substrate in a vacuum chamber of a vapor deposition apparatus for performing vapor deposition. More specifically, each organic layer forming material is heated and evaporated in a heating section located in a vapor deposition source, and the evaporated organic layer forming material (evaporated material) is radially discharged from a nozzle provided at the vapor deposition source to deposit onto an anode layer formed on the substrate. The organic layer forming material is thereby vapor-deposited on the anode layer.
In such vacuum vapor deposition, what is called a batch process or a roll process is employed. A batch process is a process in which an organic layer is vapor-deposited on an anode layer for each of substrates each including an anode layer formed thereon. Meanwhile, a roll process is a process in which a strip-shaped substrate including an anode layer formed thereon, which has been rolled up, is continuously unwound (what is called a roll-to-roll manner), the unwound substrate is supported by a surface of a can roller, which rotates, to move the substrate along with the rotation to sequentially vapor-deposit respective organic layers on the anode layer, and the substrate with the respective organic layers vapor-deposited thereon is rolled up again. From among these processes, it is desirable that organic devices be manufactured using the roll process from the perspective of cost reduction.
For forming a plurality of layers on an anode layer when manufacturing an organic EL device using the roll process in vacuum vapor deposition as described above, in order to form respective organic layers of desired patterns, the organic layers are sequentially deposited on the anode layer via a what is called a shadow mask including opening portions. Furthermore, in order to deposit the respective layers with high position accuracy, alignment is required for the respective layers. Accordingly, use of an alignment mechanism for adjusting displacements of respective organic layers in the organic layer formation using such shadow mask has been proposed (cf., Patent. Document 1)
Patent Document 1 discloses that a displacement in a direction perpendicular to a direction of movement of a substrate (TD direction) is detected by recognizing a pattern or alignment marks of an organic light-emitting layer (organic layer) by means of an image recognition camera and adjusted by adjusting the positions and angles of a pair or guide rollers, while a displacement in the direction of movement of the substrate (MD direction) is adjusted by adjusting the passage route of the substrate by means of an accumulator.